Sea-level study brings good and bad news to Hampton Roads

David Malmquist in the Virginia Institute of Marine Science News: A new study of local sea-level trends by researchers at the Virginia Institute of Marine Science (VIMS) brings both good and bad news to localities concerned with coastal inundation and flooding along the shores of Chesapeake Bay.

Dr. John Boon, the study’s lead author, says the good news is that “absolute sea level in Chesapeake Bay is rising only about half as fast as the global average rise rate.” The bad news, says Boon, is that “local subsidence more than makes up for it.” Boon has previously warned of the long-term impacts of sea-level rise in Hampton Roads, particularly in light of the increased likelihood of coastal flooding during hurricanes and nor’easters.

In their report, Boon and his co-authors, VIMS professor John Brubaker and assistant research scientist David Forrest, stress the distinction between absolute sea level—a measure of the volume and mass of ocean water, and relative sea level—the level of the ocean surface measured relative to land (and more specifically a tide gauge).

The authors note that for Chesapeake Bay, relatively moderate rates of absolute sea-level rise, when combined with locally high rates of land subsidence and an increasing coastal population, add up to a significant and growing threat. They call for continued operation of the local tide gauge network and addition of new mapping tools such as LIDAR to aid in smarter coastal planning and improved emergency-response measures….

A lithograph of the battle between the Monitor and Merrimac--fought March 9th 1862 at Hampton Roads, near Norfolk, Virginia